JUMP TO KEY SECTIONS

Before You Start: Check Your Setup
Why Isn't My ACASIS 80Gbps Pro Storage Detected?
Why Isn't My New SSD Showing Up?
Why Is My External SSD Slower Than Expected?
Why Does Performance Drop During Long Transfers?
Why Does My SSD Disconnect or Keep Dropping Out?
Why Doesn't My Storage Reconnect After Sleep?
RAID Setup and Drive Recognition Issues
Why Can't I Set the ACASIS 80Gbps Pro Storage as a macOS Startup Disk?
Is It Normal for the Device to Get Hot?
Still Need Help?

Before You Start: Check Your Setup

Before troubleshooting a specific issue, it's worth checking the basics. 

1. Confirm Your Computer Supports a Compatible High-Speed Interface

The ACASIS 80Gbps Pro Storage (TB504 Pro/TB504/TB504 Air) is designed for computers with compatible high-speed connections, including:

• - Thunderbolt 5 Port
• - Thunderbolt 4 Port
• - Thunderbolt 3 Port
• - USB4 Port

For the best compatibility and performance, check your computer manufacturer's specifications to confirm the capabilities of the USB-C or Thunderbolt port you're using.

2. Connect Your Computer to the Correct Port

Use the port marked with the computer/Host icon to connect the ACASIS storage device to your computer.

Other ports may be designed for expansion or downstream connections and should not be used as a substitute for the primary Host connection.

3. Use a Certified High-Speed Cable

For troubleshooting and maximum performance, we recommend starting with the cable included with your ACASIS device or another certified cable that supports the required Thunderbolt 5/4 or USB4 specification. A cable with insufficient bandwidth or an unreliable connection can cause slower speeds, intermittent disconnects, or failure to establish a high-speed connection.

Why Isn't My ACASIS 80Gbps Pro Storage Detected?

If your ACASIS 80Gbps Pro Storage isn't showing up on your computer, work through the following checks.

Step 1: Check the Power Connection

First, confirm that the device is receiving power and that its power indicator is operating normally.

If the device does not power on:

1. Reconnect the power adapter.
2. Try a different wall outlet.
3. Disconnect the SSDs and data cable, then restart the device.

If the device still does not power on after checking the power connection, please contact ACASIS Support for further assistance.

Step 2: Check the Host Connection

Make sure that:

• - The computer is connected to the Host port.
• - The cable supports Thunderbolt 5/4 or USB4 data transmission.
• - The computer port itself supports a compatible high-speed protocol.

If possible, try a different compatible port on your computer and reconnect the device using a known-working cable.

Step 3: Check Whether Your System Sees the Device

On macOS

Go to: Apple menu → About This Mac → More Info → System Report → Thunderbolt / USB4

Check whether the ACASIS device appears in the connected device list.

On Windows

Open Device Manager and check relevant sections such as:

• - Disk drives
• - Disk Management
• - Universal Serial Bus controllers
• - Thunderbolt controllers, where applicable

If the device does not appear anywhere after checking the cable and connection, further troubleshooting may be required.

Step 4: Windows Users—Check Thunderbolt Drivers and Authorization

Some Windows PCs require the appropriate Thunderbolt drivers and software before Thunderbolt accessories can work correctly.

You may want to:

1. Download and open the Thunderbolt Control Center, if supported by your PC, and confirm that the connected device has been authorized.

2. Use the Intel® Driver & Support Assistant to check for available Intel driver and software updates.

3. Check your computer manufacturer's support page for the latest Thunderbolt, chipset, or BIOS updates specific to your PC model.

Note: Driver availability and Thunderbolt support can vary by computer manufacturer and model. For the most compatible drivers, we recommend checking your PC manufacturer's support page first.

Why Isn't My New SSD Showing Up?

If the ACASIS device is detected but a newly installed SSD doesn't appear as a usable drive, the SSD may simply need to be initialized and formatted. This is common with brand-new SSDs.

Important: Formatting or erasing a drive deletes its data. Do not erase an SSD containing files you need unless you have backed them up.

On macOS

1. Open Disk Utility.
2. Select the SSD.
3. Choose Erase.
4. Select a format appropriate for your workflow.
5. Complete the formatting process.

On Windows

1. Right-click the Start button and select Disk Management.
2. Locate the new SSD.
3. Initialize the disk if prompted.
4. Create a new volume and format it.

Why Is My External SSD Slower Than Expected?

One of the most common questions we receive is: "Why isn't my SSD reaching the advertised speed?"

The answer is that storage performance is determined by the entire system. The maximum speed of your SSD enclosure does not automatically guarantee that every SSD, computer, cable, or workload will reach the same number.

Performance can be affected by:

• - Your computer's Thunderbolt 5/4/3 or USB4 specification
• - The negotiated connection mode
• - SSD model and controller performance
• - Cable capability
• - File size and workload
• - Available SSD capacity
• - Cache behavior during sustained writes
• - Operating system and background activity
• - Benchmark software and test settings

Read Speed Is High, but Write Speed Is Lower—Is That Normal?

In many cases, yes. SSD read and write performance are not always identical. Write performance can be affected by the SSD's cache design, NAND configuration, available free space, and sustained workload.

For example, an SSD may deliver excellent short-burst write performance and then slow down during a large, continuous transfer after its high-speed cache is exhausted. This behavior is determined primarily by the SSD's own design and workload conditions.

A lower write speed does not automatically mean there is a problem with your ACASIS Pro storage device.

Some suggestions

Mac Users: Check Your Connection Environment

When multiple high-bandwidth devices are connected to the same computer, available bandwidth may be shared depending on the system architecture.

If your speed is unexpectedly low, try:

• - Disconnecting other high-bandwidth peripherals temporarily.
• - Connecting the ACASIS device to another compatible port.
• - Testing the storage device with minimal other peripherals connected.

Windows Users: Check Your Disk Performance Policy

Windows may provide different performance policies for external storage devices.

You can check these settings by going to: Device Manager → Disk drives → Select your SSD → Properties → Policies

Please read the Windows prompts carefully before changing any settings. Some performance settings may require you to use Safely Remove Hardware before disconnecting the drive to reduce the risk of data loss.

Why Does Performance Drop During Long Transfers?

If your storage performs well initially but slows down during a long transfer, the most common causes are SSD temperature and sustained-write behavior.

Keep the Device Properly Ventilated

During demanding workloads such as editing high-resolution video, transferring large project files, or running multiple SSDs simultaneously, internal components generate significant heat.

Place the device on a hard, flat surface with sufficient airflow around it. Avoid covering the enclosure during use.

Make Sure the SSD Has Good Thermal Contact

Proper installation of the thermal material helps transfer heat away from the SSD.

Make sure the SSD is installed securely and that the thermal pad or other included thermal material is positioned correctly according to the product instructions.

Understand Sustained Write Performance

Long, continuous transfers can reduce performance even when temperatures are under control. Many SSDs use high-speed cache technology that delivers faster performance for shorter workloads. Once that cache is filled, the drive may transition to its lower sustained-write speed.

For very large workloads, allowing the SSD time to cool down and recover between intensive tasks may help maintain more consistent performance.

Choose the Right File System for Your Workflow

File system choice can affect compatibility and performance.

• - APFS is generally well suited to SSDs used primarily with macOS.
• - exFAT offers broad compatibility between macOS and Windows.

Choose the format based on how and where you plan to use the drive rather than speed alone.

Why Does My SSD Disconnect or Keep Dropping Out?

An external SSD that disappears unexpectedly can be frustrating. The cause may be related to the cable, temperature, power management, SSD behavior, or the host system.

1. Check the Cable First

For intermittent disconnects, the cable is one of the first things to test.

Try:

• - Using the original ACASIS cable.
• - Testing with another certified Thunderbolt 5/4/3 or USB4 cable.
• - Connecting directly to your computer instead of through another hub or adapter.

A cable that does not fully support the required bandwidth or has an unstable connection may cause intermittent detection or disconnects.

2. Check SSD Temperature

High temperatures can cause SSDs to reduce performance to protect themselves. In demanding situations, excessive heat may also affect overall stability.

Make sure:

• - The enclosure has adequate airflow.
• - The SSD has been installed with the included thermal material.
• - The device is not covered during high-load operation.

3. Check Whether the Issue Happens After Sleep

If the drive disconnects mainly when your computer enters or exits sleep, the issue may be related to operating system power management rather than the storage hardware itself.

See the section below for sleep and wake troubleshooting.

4. Check the SSD Itself

SSDs vary in controller design, firmware, power consumption, and behavior under sustained workloads.

If the problem occurs with only one particular SSD, try:

1. Checking whether the SSD manufacturer offers a firmware update.
2. Testing the ACASIS device with another compatible SSD.
3. Recording the SSD model, capacity, and firmware version before contacting ACASIS Support.

5. Check the Physical Connection

After disconnecting power, inspect the SSD and its connector for dust, contamination, or signs of damage.

Make sure the SSD is fully seated in its slot before testing again.

Why Doesn't My Storage Reconnect After Sleep?

If your ACASIS storage device works normally before sleep but does not immediately reconnect after your computer wakes up, the issue may be related to how the operating system manages external devices during sleep and wake cycles.

On macOS

Try the following:

• - Check your Mac's sleep and external storage settings.
• - Wait a few seconds after waking your Mac to allow connected devices to initialize.
• - Reconnect the device if it does not reappear.

On Windows

Windows power management settings can affect how USB and Thunderbolt devices behave during sleep.

Consider checking:

• - Your Windows power mode.
• - USB power-saving settings, including USB selective suspend where applicable.
• - Power management settings for relevant controllers.

You may also want to check your PC manufacturer's support page for BIOS, chipset, or Thunderbolt driver updates.

RAID Setup and Drive Recognition Issues

The Acasis 80Gbps Pro Storage Series supports software RAID configurations through the operating system, including RAID 0, RAID 1, RAID 10, and more. However, unlike traditional multi-bay storage systems, the TB504 and TB504 Air features a next-generation independent bandwidth architecture. This means each SSD can achieve near-interface maximum performance individually — even without RAID 0.

RAID configurations require multiple SSDs to work together as a single storage arrangement. Before configuring RAID, make sure every installed SSD is individually detected and functioning correctly.

For the Best Experience, Use Similar SSDs

For greater consistency, we recommend using SSDs with matching or similar:

• - Models
• - Capacities
• - Performance specifications
  

Mixing SSDs with different capacities or performance characteristics can limit the usable capacity or affect the overall behavior of the RAID configuration.

Configure RAID Before Formatting for Your Workflow

If you plan to create a RAID volume, complete the RAID configuration first and then initialize or format the resulting volume as required by your operating system or RAID software.

Important: Creating, modifying, or rebuilding a RAID configuration can erase existing data. Always back up important files before changing a RAID setup.

If a RAID setup fails, check that all SSDs are properly installed and recognized before starting the configuration again.

Why Can't I Set the ACASIS 80Gbps Pro Storage as a macOS Startup Disk?

If your Mac detects the ACASIS 80Gbps Pro Storage but you can't use the external SSD as a startup disk, check the following two items first.

1. Check Your Mac's Chip Series and Thunderbolt Port

First, identify whether your Mac uses an Intel processor or Apple silicon.

Tip: If you're experiencing an issue when using the external SSD as a startup disk, connect the ACASIS storage device to the Thunderbolt port closest to the power connector on your Mac and try again.

2. Make Sure the SSD Is Formatted as APFS

The SSD should be formatted as APFS (Apple File System) when you intend to use it as a macOS startup disk.

If the SSD is currently formatted as another file system, such as exFAT, formatting or permission-related issues may prevent it from being used as a startup disk.

How to Check the Format on macOS

1. Open Disk Utility.
2. Select the external SSD.
3. Check the Format information.
4. Confirm that the SSD is formatted as APFS.

Is It Normal for the Device to Get Hot?

Yes. It is normal for a high-performance storage enclosure to become warm—or noticeably hot—during demanding workloads.

The ACASIS 80Gbps Pro Storage uses a high-conductivity aluminum enclosure and a large-surface thermal design to move heat away from internal components and release it into the surrounding air.

This means the enclosure itself can become warm because it is actively transferring heat away from the SSDs and internal electronics.

For Safe and Stable Operation

• - Keep the device in a well-ventilated area.
  
• - Do not cover the enclosure during operation.
• - After a long period of high-load transmission, allow the device to cool down for 2 to 3 minutes.
• - When running multiple SSDs simultaneously, ensure adequate airflow around the device.

If the device becomes unusually hot, repeatedly disconnects, or stops functioning normally, stop using it and contact ACASIS Support for assistance.

Still Need Help?

If you're still experiencing an issue after following the troubleshooting steps above—or if the issue you're experiencing isn't covered in this guide—our support team is here to help.

Before Contacting ACASIS Support Team

For the fastest and most accurate troubleshooting, please check the following first:

1. Confirm your computer supports Thunderbolt 5/4/3 or USB4.

2. Connect the computer to the correct Host port.

3. Test with the original or a certified high-speed cable.

4. Check whether the device appears in macOS System Report or Windows Device Manager.

5. Confirm that new SSDs have been initialized and formatted.

6. Check SSD temperature and ventilation during high-load use.

7. Test with another compatible SSD if possible.

8. Check for relevant SSD firmware or computer driver updates.

9. Disconnect other high-bandwidth peripherals and test again.

Contact ACASIS Support

If the issue persists, please email us at support@acasis.com. To help us identify the cause more quickly, please include as much of the following information as possible:

• - Computer model and operating system version
• - Port type used to connect the ACASIS device
• - SSD brand, model, and capacity
• - Cable type or cable model, if known
• - A brief description of the issue, including when and how it occurs
• - Screenshots of System Report, Device Manager, or speed-test results, if relevant
• - Photos or a short video showing the issue, if applicable

The more details you provide about your setup, the faster we can narrow down the possible cause and help you find a solution.

Frequently Asked Questions

Q1: What type of port does the ACASIS 80Gbps Pro Storage support?

A1: The ACASIS 80Gbps Pro Storage is designed to work with computers equipped with a Thunderbolt 5, Thunderbolt 4, Thunderbolt 3, or USB4 port. Other standard USB ports are not supported.

Please note that USB-C refers to the physical connector shape and does not necessarily indicate Thunderbolt or USB4 compatibility. Devices such as smartphones and iPads with standard USB-C ports are not supported.

Q2: Why is my SSD detected but not visible in Finder or File Explorer?

A2: A new SSD may need to be initialized, partitioned, or formatted before it can be used. Check Disk Management on Windows or Disk Utility on macOS.

Q3: Why is my Thunderbolt 5 SSD enclosure slower than its advertised maximum speed?

A3: Advertised interface speeds represent the capability of the connection under ideal conditions. Actual performance depends on your computer, SSD, cable, workload, available bandwidth, and system configuration.

Q4: Is it normal for an external SSD enclosure to get hot?

A4: Yes. High-speed SSDs and controllers generate heat during intensive workloads, and a metal enclosure is designed to transfer that heat away from internal components. Keep the device properly ventilated and avoid covering it during use.

Q5: Why does my external SSD disappear during a file transfer?

A5: Common causes include an unstable cable connection, excessive temperature, SSD-specific behavior, or system power management. Start by testing the original cable, checking ventilation, and trying another compatible SSD if available.